1. Field of the Invention
This invention relates generally to printing systems, and more particularly to printing systems for printing characters in various fonts and formats onto webs of sheet stock of various widths, for cutting the web to various lengths to accommodate the various formats and for automatically stacking the tags after they are cut.
2. Description of the Prior Art
Printers capable of printing characters in various fonts and formats onto webs of various sizes are known. One such printer is described in U.S. Pat. application Ser. No. 151,577 filed by Frederick M. Pou on May 20, 1980, now U.S. Pat. No. 4,327,696, incorporated herein by reference.
While prior art printers such as the one described in the aforementioned U.S. Pat. application Ser. No. 151,577 do provide a way to print characters of various fonts and formats onto various size webs of sheet stock, such printers can be augmented to incorporate additional features. The prior art printers generally print the required information onto the web in the desired format and then cut the web into tags of a predetermined length containing one or more tag sections. For purposes of discussion each section thus cut will be referred to as a tag regardless of the number of tags actually printed on the section. The individual tags printed on each tag will be referred to as tag sections. Moreover, since the printer according to the invention is capable of printing onto various types of web stock including, for example, stock that can be cut into labels, cards or the like, the term tags is intended to cover sections cut from various web stock, and is not limited to merchandise tags.
In a typical printer, after the tags are printed and cut, they exit the printer through a conduit such as a chute, and when a stacker is used, are expelled onto a conveyor belt within the stacker. Afterward the tags are removed from the stacker in stacks. In such stackers, the tags may be stacked in a shingle mode or in piles. However, the stacking mode cannot be readily altered, and in the stacking in piles mode, the spacing between the piles must be great enough to accommodate the widest tags that are printed. This results in a reduction in stacker capacity for narrow tags.
The tags are generally printed in batches ranging from a few tags to hundreds of tags per batch. Typically, the tags in each batch are very similar in size and shape, and differ from tags in other batches only by an item of information, such as, for example, a price or item code. Consequently, because of the physical similarity of the tags of different batches, it is difficult and time consuming for the operator to separate the various batches of tags, and frequently the operator is required to read a large number of tags in order to make the separation.
In the prior art printers, when one or more tags become lodged in the exit conduit or chute, printing is terminated when the jam is detected. Unfortunately, in many instances, the jam is not detected until a large number of tags back up in the chute. However, because the number of tags present in the chute at the time the printing is terminated is generally much larger than the number of tags in a typical batch, tags from several batches become mixed up in the chute. These tags must then be manually resorted by the operator into their proper order in the various batches before printing can be resumed. This results in a considerable delay in the printing process.
In the prior art printers the wrong size web for a given format can be loaded into the printer and result in the printing of wrong size tags for a given format. When the web used is too wide for the selected format, the result is that many tags may be wasted before the error is detected. In the case where the web is too narrow for the selected format, damage to the printing head or other machine components can occur. Such damage can be costly both in terms of the actual cost of repair to the machine, and in lost production while the machine is down.
In the prior art printers, the position at which the various lines are printed on a tag varies from printer to printer as a result of mechanical tolerances. While in many instances, the variation in line print position may not be objectionable, in other instances, it can be significant, particularly when multiple printers are being operated simultaneously, and the tags from the various printers can be readily compared.
The stackers associated with the prior art printers are generally able to stack in only a single mode (either a shingle mode or a stack in piles mode), even though, in many instances, it is desirable to change the stacking mode of a stacker to accommodate various tags or operating conditions.